Safety appliance for drill chucks



July 3H, i923;

D. B. NELLER TY APPLIANCE FOR DRILL CHUCKS SAFE Filed March 2l, 1918 Patented July si, 192sD nENvEn BnowN'wnLLnRgor WAsH1NG'roNn1srnrc'r or COLMBIA.'

SAFETY Armin-Non ron DRILL cHU'cKs.

- iApplcaton filed. March 21, 1918. Serial No."223,7t56.-

To all whom may ooacewt 4 Be it known that I, DENVER BROWN VEL- LER, a citizen of theUnited States, residing out interfering with :the constantspeed' of jaws.

the machine. 1

Heretofore, in drill chucks in which there is employed a plurality of radially movable jaws, there is also provided-a sleeve member which encircl'es the jaws and the movementof the sleeve member, either rotary, reciprocating or combined rotary and reciprocating, causes by its peculiar interior construction, an inward orV outward movement of the These sleeve members all .have a limited-range ofmoveinent in causing the jaws to open torelease'th'e tool and are usually provided with'a spring means to return the sleeve to its normal or closing position.

In use thechuck is associated with any suit- 4able power mechanism to impart a rotary motion to the same and is-usually'revolved at the rate of 200 or 300 revolutions per minute. Shouldit become necessary` to change the tool, for` lany reason whatsoever, the machine wouldhave 4to be stopped to enable a safe and positive manipulation of the sleeve; this causes considerable valuable time to be lost and also a heavy wear and'tear on the machine caused by this continual starting and stopping. In numerous cases it h as been attempted to operate the chuck while the same is revolving at this high rate of speed and has resulted in serious injury to the operator, such as burning or tearing the flesh of his hand or in some cases breaking his arm. This happens because the sleeve "member, when gripped while 'the chuck is rotated at high speed, is almost instantaneously moved through its limited range of movement and' then continues to revolve with the chuck.

It is therefore broadlyl contemplated in the present invention, to provide a structure used in connection with Jthe rotary chuck by which the sleeve member may not only be opened to the limit of its movement, but held in that position indefinitely` while the ma# chine is in constant operation, without iii--v curring any, ofv the aforesaid detrimental results.

Another object of the invention residesin the ability to either remove or ,insert a tool while the machine is in operation. Y

With these and other objects. in view,not speciiically'mentioned, as will be apparent to those skilled in the art, I'will now describe my invention in detailso as to enable I the same to be made and used.

In the accompanying drawings, which'are to be taken asa part of this specification, and in whichI have shown merely preferred forms of embodiments of the invention,- Figure l is'afrontelevation 'of ajcommo'n" type u of drill .chuck showing .the safety gripping device attachedithereto, Fig. 2 is a' view,

partly in section, showing the manner .of

associating the band with the chuck, F ig. 3 is a perspective view of the f gripping mem- "ber, as shown in Figs. land 2, Fig.4 tV is a modified form, partly in'section, Vshowing the manner of associating the band with ya. f form of chuck now on themarket, Fig.5.is

a yperspective view of the band used in Fig. 4, and Fig. 6 is a transversefsectional view i taken through the chuck illustrating the radially movable jaws. I

' As to the type of'dr'ill chuck shown in the drawings, it might be well to here statethat it is known as the VVahlstrom chuck and I have only illustrated, for the sake` of clearness, the outside appearance l.of the' same, as I wish itunderstoodthat my devicevcan be attached toany type in' which there isem'- ,ployed radiallymov'able 'j aws anda member encircling the same, the said member constituting an operating means fortopening'or closing the jaws by either an oscillatory,

lOO

and the surface ofthe sleeve therebetween Y is preferably lsmooth as indicated Vat '5f Mounted upon the chuck between the shoulders 3 and 4 is a contractible band 6 which is split transversely, preferably onl a diago- 

